{"id":"CVE-2026-4258","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-4258","generatedAt":"2026-10-28T05:26:18.314Z","title":"Versions of the package sjcl before 1.0.9 are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey().","description":"Versions of the package sjcl before 1.0.9 are vulnerable to Improper Verification of Cryptographic Signature due to missing point-on-curve validation in sjcl.ecc.basicKey.publicKey(). An attacker can recover a victim's ECDH private key by sending crafted off-curve public keys and observing ECDH outputs. The dhJavaEc() function directly returns the raw x-coordinate of the scalar multiplication result (no hashing), providing a plaintext oracle without requiring any decryption feedback.","published":"2026-03-17T06:16:19.000Z","lastModified":"2026-07-28T16:18:22.000Z","status":"Modified","sourceIdentifier":"report@snyk.io","cvss":{"version":"4.0","score":7.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-347","CWE-325"],"affected":["bitwiseshiftleft/stanford javascript crypto library"],"epss":{"score":0.00255,"percentile":0.1703,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47","tags":["Exploit","Mitigation","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://github.com/bitwiseshiftleft/sjcl/blob/master/core/ecc.js%23L454-L461","tags":["Broken Link"],"source":"report@snyk.io"},{"url":"https://github.com/bitwiseshiftleft/sjcl/commit/ee307459972442a17beebc29dc331fffd8aff796","tags":["Patch"],"source":"report@snyk.io"},{"url":"https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15751243","source":"report@snyk.io"},{"url":"https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617","tags":["Exploit","Third Party Advisory"],"source":"report@snyk.io"},{"url":"https://gist.github.com/Kr0emer/2560f98edb10b0b34f2438cd63913c47","tags":["Exploit","Mitigation","Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.snyk.io/vuln/SNYK-JS-SJCL-15369617","tags":["Exploit","Third Party Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-4258","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}